ABSTRACT
Corn (Zea mays L.), known in much of the world as maize, is the world’s third most important cerealafterwheatandrice.Cornisgrownprimarilyforgrainandsecondarilyforfodderandraw materialforindustrialprocesses.Thegrainisusedforbothhumanandanimalconsumption.The vegetativepartsoftheplantarecutgreenandeitherdriedormadeintosilageforanimalfeed. ThedomesticationandselectionofcornprobablybeganincentralorsouthwesternMexicoabout 7000 years ago (Goodman, 1988). The date of origin for cultivated maize in the highlands of centralMexicoisunknown,butPalomeroToluqueñowasconsideredanancientindigenousraceby Wellhausenetal.(1952).Kato(1984)proposedamulticenterdomesticationofmaize,withtwoof thefourcentersincentralMexico.Highlandmaizeprobablycamefromthehigheraltitudecenters. ExcavationsatTeotihuacán,intheValleyofMexico,haveuncoveredearswiththecharacteristics of Cónico (Wellhausen et al., 1952), indicating that maize, similar to current types, was important fortheancientcivilizationsofhighlandMexicoandhasbeencultivatedataltitudesabove2000m formillennia(EaglesandLothrop,1994).ThedistinguishablegroupsofcultivarsaroseinMexico andCentralAmerica,inthenortheasternUnitedStates,onthenortherncoastofSouthAmerica,in theAndes,andincentralBrazil.TheSpanishandPortuguesequicklydistributedcornthroughout the world in the sixteenth century (Jones, 1985). It is now grown in more countries than any other cereal and has produced the largest grain yield of any cereal.
